Autophagy is a lysosomal degradation pathway in both animals and plants that is essential for development, differentiation, homeostasis, and survival. In animals, autophagy serves principally as an adaptive mechanism to protect organisms against diverse pathologies, including infection, cancer, neurodegeneration, heart disease, and aging. The repertoire of routine housekeeping functions performed by autophagy includes elimination of defective proteins and organelles, prevention of the accumulation of abnormal protein aggregates, and elimination of intracellular pathogens. The autophagy pathway is uniquely capable of degrading entire organelles, such as mitochondria, peroxisomes, and endoplasmic reticulum.
Multiple reports indicate that proteins required for autophagy induction, such as sirtuin 1, have reduced expression in aged tissues; levels of autophagy have been shown to diminish with age. Reduced levels of autophagy have also been associated with obesity, diabetes, cancer, neurodegenerative diseases, cardiovascular disease, osteoarthritis, and age-related macular degeneration.
A number of compounds that stimulate autophagy have been identified, including rapamycin, resveratrol, metformin, spermidine, and glucosamine.
Urolithins are ellagitannin- and ellagic acid-derived metabolites produced, e.g., by mammalian colonic microflora, including human colonic microflora. Urolithins are known to exhibit anti-oxidant activity.